1. Field of the Invention
This invention relates to microwave antennas and, more particularly, to a low cost conical corrugated feed horn for use in an offset parabolic microwave antenna.
2. Statement of the Problem
A need exists for low-cost microwave feed horns for use in offset satellite dish antennas that are small in size and low in cost. Yet, the feed horn should exhibit superior reception characteristics. The feed horn also should provide higher gain and narrower beamwidth especially when used with small offset parabolic dishes (e.g., 18-inch-diameter dishes) where interference from neighboring satellites and signal levels are of primary concern. The feed horn should also provide lower sidelobe levels that reduce reflection effects from ground objects and that also reduce interference from neighboring satellites. The feed horn should also exhibit greater bandwidth so that it can be used for both the Fixed Satellite Service (FSS) and Broadcast Satellite Service (BSS) satellite bands. The feed horn should also provide nearly equal E & H plane patterns. Finally, the feed horn should provide an axial ratio for circular polarization of less than 1 dB.